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Updated: May 7, 2026
High-resolution In Vivo Manual Segmentation Protocol for Human Hippocampal Subfields Using 3T Magnetic Resonance Imaging
Published on: November 10, 2015
Histology-derived volumetric annotation of the human hippocampal subfields in postmortem MRI
Daniel H Adler1, John Pluta, Salmon Kadivar
1Penn Image Computing and Science Laboratory (PICSL), Department of Radiology, University of Pennsylvania, 3600 Market Street, Suite 370, Philadelphia, PA 19104, USA; Department of Bioengineering, University of Pennsylvania, USA.
Abstract:
Recently, there has been a growing effort to analyze the morphometry of hippocampal subfields using both in vivo and postmortem magnetic resonance imaging (MRI). However, given that boundaries between subregions of the hippocampal formation (HF) are conventionally defined on the basis of microscopic features that often lack discernible signature in MRI, subfield delineation in MRI literature has largely relied on heuristic geometric rules, the validity of which with respect to the underlying anatomy is largely unknown. The development and evaluation of such rules are challenged by the limited availability of data linking MRI appearance to microscopic hippocampal anatomy, particularly in three dimensions (3D). The present paper, for the first time, demonstrates the feasibility of labeling hippocampal subfields in a high resolution volumetric MRI dataset based directly on microscopic features extracted from histology. It uses a combination of computational techniques and manual post-processing to map subfield boundaries from a stack of histology images (obtained with 200μm spacing and 5μm slice thickness; stained using the Kluver-Barrera method) onto a postmortem 9.4Tesla MRI scan of the intact, whole hippocampal formation acquired with 160μm isotropic resolution. The histology reconstruction procedure consists of sequential application of a graph-theoretic slice stacking algorithm that mitigates the effects of distorted slices, followed by iterative affine and diffeomorphic co-registration to postmortem MRI scans of approximately 1cm-thick tissue sub-blocks acquired with 200μm isotropic resolution. These 1cm blocks are subsequently co-registered to the MRI of the whole HF. Reconstruction accuracy is evaluated as the average displacement error between boundaries manually delineated in both the histology and MRI following the sequential stages of reconstruction. The methods presented and evaluated in this single-subject study can potentially be applied to multiple hippocampal tissue samples in order to construct a histologically informed MRI atlas of the hippocampal formation.
Insights
This study maps hippocampal subfield boundaries using histology and high-resolution MRI. This method allows for accurate subfield labeling, crucial for understanding brain anatomy and developing a histologically informed MRI atlas.
Area of Science:
- Neuroimaging
- Neuroanatomy
- Computational Biology
Background:
- Magnetic resonance imaging (MRI) is increasingly used for hippocampal subfield morphometry.
- Current MRI-based subfield delineation relies on unvalidated geometric rules due to limited data linking MRI to microscopic anatomy.
- Accurate 3D mapping of hippocampal subfields is essential for understanding their structure and function.
Purpose of the Study:
- To demonstrate the feasibility of labeling hippocampal subfields in MRI data directly from microscopic histological features.
- To develop and evaluate computational methods for mapping histology-derived boundaries onto high-resolution MRI.
- To lay the groundwork for creating a histologically informed MRI atlas of the hippocampal formation.
Main Methods:
- A novel pipeline combining computational techniques and manual post-processing was used.
- Histology images were reconstructed in 3D and co-registered to a postmortem 9.4T MRI scan of the hippocampal formation.
- Graph-theoretic algorithms and iterative affine/diffeomorphic co-registration were employed to align histology and MRI data.
Main Results:
- The study successfully mapped hippocampal subfield boundaries from histology onto high-resolution MRI.
- Reconstruction accuracy was evaluated by measuring displacement errors between manually delineated boundaries.
- This represents the first demonstration of labeling hippocampal subfields directly from microscopic features in MRI.
Conclusions:
- The presented methods enable direct, histology-informed labeling of hippocampal subfields in MRI.
- This approach overcomes limitations of heuristic geometric rules in MRI-based subfield analysis.
- The methodology can be extended to create a comprehensive, histologically accurate MRI atlas of the hippocampal formation.
